gddo-server: centralize config and add log package

This change starts centralizing the configuration for godoc.org. In the
future all configuration, including an environment variable and metadata
server check will go through viper.

This change also adds the new logging library I am writing. In the future
all logging will go through this library.

Change-Id: Id0bed0f3a4dc9acb109545db89d6221a182c37fe
Reviewed-on: https://go-review.googlesource.com/34618
Reviewed-by: Tuo Shan <[email protected]>

gddo-server/background.go

@@ -1,4 +1,4 @@
-// Copyright 2013 The Go Authors. All rights reserved.
+// Copyright 2017 The Go Authors. All rights reserved.
 //
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file or at
@@ -7,52 +7,54 @@
 package main
 
 import (
-	"flag"
 	"log"
 	"time"
 
+	"github.com/spf13/viper"
 	"google.golang.org/appengine"
 
 	"github.com/golang/gddo/database"
 	"github.com/golang/gddo/gosrc"
 )
 
-var backgroundTasks = []*struct {
+type BackgroundTask struct {
 	name     string
 	fn       func() error
-	interval *time.Duration
+	interval time.Duration
 	next     time.Time
-}{
-	{
-		name:     "GitHub updates",
-		fn:       readGitHubUpdates,
-		interval: flag.Duration("github_interval", 0, "Github updates crawler sleeps for this duration between fetches. Zero disables the crawler."),
-	},
-	{
-		name:     "Crawl",
-		fn:       doCrawl,
-		interval: flag.Duration("crawl_interval", 0, "Package updater sleeps for this duration between package updates. Zero disables updates."),
-	},
 }
 
 func runBackgroundTasks() {
 	defer log.Println("ERROR: Background exiting!")
 
+	var backgroundTasks = []BackgroundTask{
+		{
+			name:     "GitHub updates",
+			fn:       readGitHubUpdates,
+			interval: viper.GetDuration(ConfigGithubInterval),
+		},
+		{
+			name:     "Crawl",
+			fn:       doCrawl,
+			interval: viper.GetDuration(ConfigCrawlInterval),
+		},
+	}
+
 	sleep := time.Minute
 	for _, task := range backgroundTasks {
-		if *task.interval > 0 && sleep > *task.interval {
-			sleep = *task.interval
+		if task.interval > 0 && sleep > task.interval {
+			sleep = task.interval
 		}
 	}
 
 	for {
 		for _, task := range backgroundTasks {
 			start := time.Now()
-			if *task.interval > 0 && start.After(task.next) {
+			if task.interval > 0 && start.After(task.next) {
 				if err := task.fn(); err != nil {
 					log.Printf("Task %s: %v", task.name, err)
 				}
-				task.next = time.Now().Add(*task.interval)
+				task.next = time.Now().Add(task.interval)
 			}
 		}
 		time.Sleep(sleep)
@@ -86,7 +88,7 @@ func doCrawl() error {
 	}
 	if _, err = crawlDoc("crawl", pdoc.ImportPath, pdoc, len(pkgs) > 0, nextCrawl); err != nil {
 		// Touch package so that crawl advances to next package.
-		if err := db.SetNextCrawl(pdoc.ImportPath, time.Now().Add(*maxAge/3)); err != nil {
+		if err := db.SetNextCrawl(pdoc.ImportPath, time.Now().Add(viper.GetDuration(ConfigMaxAge)/3)); err != nil {
 			log.Printf("ERROR db.SetNextCrawl(%q): %v", pdoc.ImportPath, err)
 		}
 	}

gddo-server/client.go

@@ -1,4 +1,4 @@
-// Copyright 2013 The Go Authors. All rights reserved.
+// Copyright 2017 The Go Authors. All rights reserved.
 //
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file or at
@@ -10,39 +10,35 @@
 package main
 
 import (
-	"flag"
 	"fmt"
 	"net"
 	"net/http"
 	"os"
-	"time"
 
 	"github.com/gregjones/httpcache"
 	"github.com/gregjones/httpcache/memcache"
+	"github.com/spf13/viper"
 
 	"github.com/golang/gddo/httputil"
 )
 
-var (
-	dialTimeout    = flag.Duration("dial_timeout", 5*time.Second, "Timeout for dialing an HTTP connection.")
-	requestTimeout = flag.Duration("request_timeout", 20*time.Second, "Time out for roundtripping an HTTP request.")
-)
-
 func newHTTPClient() *http.Client {
 	t := newCacheTransport()
+
+	requestTimeout := viper.GetDuration(ConfigRequestTimeout)
 	t.Transport = &http.Transport{
 		Proxy: http.ProxyFromEnvironment,
 		Dial: (&net.Dialer{
-			Timeout:   *dialTimeout,
-			KeepAlive: *requestTimeout / 2,
+			Timeout:   viper.GetDuration(ConfigDialTimeout),
+			KeepAlive: requestTimeout / 2,
 		}).Dial,
-		ResponseHeaderTimeout: *requestTimeout / 2,
-		TLSHandshakeTimeout:   *requestTimeout / 2,
+		ResponseHeaderTimeout: requestTimeout / 2,
+		TLSHandshakeTimeout:   requestTimeout / 2,
 	}
 	return &http.Client{
 		// Wrap the cached transport with GitHub authentication.
 		Transport: httputil.NewAuthTransport(t),
-		Timeout:   *requestTimeout,
+		Timeout:   requestTimeout,
 	}
 }